Current-Signature-Based Analysis of Complex Test Fails

A class of failures observed during the SEMATECH-sponsored test methods experiment was analysed. The analysis focused on use of test-based failure and I DDQ signature analysis to gain insight into the physical mechanisms underlying such failures. Multiple test methods were applied to 0.45 μm effective channel length application specific integrated circuits (ASIC), indicating existence of several difficult-to-detect and subtle fail types. The analysis highlighted techniques for understanding failure mechanisms using only tester data and have the potential to ease the difficult and expensive task of fault localization, provide a priori information on the type of failure and ultimately to point directly to root cause mechanisms.